var plugins=new Array(“image/svg-xml”, “application/x-director”, “application/x-shockwave-flash”, “audio/x-pn-realaudio-plugin”, “video/quicktime”, “application/x-mplayer2”, “application/pdf”)
The problem first came to light on WebmasterWorld (free registration required to view), although the problem did not seem to be widespread, either dependent an individual user’s current installed applications or perhaps if the issue wasn’t accross all AdSense servers/datacenters.
Four days after the problem was first reported, AdSenseAdvisor confirmed that there was an issue with the AdSense ad code prompting users to download third party applications and that the problem has been fixed.
Thanks for bringing this to our attention. We encountered some technical issues that caused some visitors using IE to see download prompts for third-party add-ons or plug-ins. Our engineers resolved the issue right away, so ad serving is now back to normal.
Don’t worry — all clicks and impressions have been recorded as usual. We’re sorry for any inconvenience, and grateful for your patience during this time.
This is a pretty significant problem, and I am surprised it took so long after it was first noticed to be corrected. I am guessing not very many of the AdSense team use IE, or they have every plugin imaginable already installed 😉